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文章目录
- 前言
- 一、Windows环境下实现TCP通信
- 1.服务器
- 2.客户端
- 3.运行
- 二、Linux环境下实现TCP通信
- 1.服务端
- 2.客户端
- 三、Qt实现TCP通信
- 1.服务端
- 1.客户端
- 总结
前言
大多数项目都在Linux系列的操作系统下开发服务器端，而多数客户端是在Windows平台下开发的。不仅如此，有时应用程序还需要在两个平台之间相互切换。因此，学习套接字编程的过程中，有必要兼顾Windows和Linux两大平台。另外，这两大平台下的套接字编程非常类似，如果把其中相似的部分放在一起讲解，将大大提高学习效率。只要理解好其中一个平台下的网络编程方法，就很容易通过分析差异掌握另一平台。因为不论什么方式实现，底层的逻辑都是完全一致的。
一、Windows环境下实现TCP通信
为了在Winsock基础上开发网络程序，需要做如下准备，以下两个文件都是系统自带的，包含时注意目标平台版本与库的版本一致。
导入头文件winsock2.h。
链接ws2_32.lib库（库名称和链接目录）。
1.服务器
#include <stdio.h>
#include <stdlib.h>
#include <WinSock2.h>void ErrorHandling(char *message){fputs(message, stderr);fputs("\n", stderr);exit(1);
}int main(int argc, char * argv[]){WSADATA wsaData;SOCKET hServSock, hClntSock;SOCKADDR_IN servAddr, clntAddr;int szClntAddr;char message[] = "Hello World!";if (argc != 2) {printf("Usage : %s <port>", argv[0]);exit(1);}if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)ErrorHandling("WSAStartup() error!");hServSock = socket(PF_INET, SOCK_STREAM, 0);if (hServSock == INVALID_SOCKET)ErrorHandling("socket() error!");memset(&servAddr, 0, sizeof(servAddr));servAddr.sin_family = AF_INET;servAddr.sin_addr.s_addr = htonl(INADDR_ANY);servAddr.sin_port = htons(atoi(argv[1]));if (bind(hServSock, (SOCKADDR *)&servAddr, sizeof(servAddr)) == SOCKET_ERROR)ErrorHandling("bind() error!");if (listen(hServSock, 5) == SOCKET_ERROR)ErrorHandling("listen() error!");szClntAddr = sizeof(clntAddr);hClntSock = accept(hServSock, (SOCKADDR*)&clntAddr, &szClntAddr);if (hClntSock == INVALID_SOCKET)ErrorHandling("accept() error!");fputs("sending message...", stderr);fputs("", stderr);send(hClntSock, message, sizeof(message), 0);closesocket(hClntSock);closesocket(hServSock);WSACleanup();return 0;
}2.客户端
#include <stdio.h>
#include <stdlib.h>
#include <WinSock2.h>
void ErrorHandling(char* message);int main(int argc, char *argv[])
{WSADATA wsaData;SOCKET hSocket;SOCKADDR_IN servAddr;char message[30];int strlen;if (argc != 3) {printf("Usage: %s <IP> <port>", argv[0]);exit(1);}if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)ErrorHandling("WSAStartup() error!");hSocket = socket(PF_INET, SOCK_STREAM, 0);if (hSocket == INVALID_SOCKET)ErrorHandling("socket() error!");memset(&servAddr, 0, sizeof(servAddr));servAddr.sin_family = AF_INET;servAddr.sin_addr.s_addr = inet_addr(argv[1]);servAddr.sin_port = htons(atoi(argv[2]));if (connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr)) == SOCKET_ERROR)ErrorHandling("connect() error!");strlen = recv(hSocket, message, sizeof(message) - 1, 0);if (strlen == -1)ErrorHandling("read() error!");printf("Message from server:%s", message);closesocket(hSocket);WSACleanup();return 0;
}void ErrorHandling(char * message) {fputs(message, stderr);fputc('\n', stderr);exit(1);
}3.运行
运行时直接进入到可执行程序文件，使用命令行运行
C:\tcpip>tcp_win_server 9190
C:\tcpip>tcp_win_client 127.0.0.1 9190
二、Linux环境下实现TCP通信
1.服务端
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
void error_handling(char *message);
int main(int argc,char *argv[])
{int serv sock;int clnt sock;struct sockaddr in serv addr;struct sockaddr in clnt addr;socklen t clnt addr size;char message[]="Hello World!";if(argc!=2){printf("Usage :%s<port>\n",argv[0]);exit(1);}serv sock=Socket(PF INET,SOCK STREAM，0);if(serv sock ==-1)error_handling("socket() error");memset(&serv_addr,0,sizeof(serv addr));serv_addr.sin_family=AF INET;serv_addr.sin_addr.s addr=htonl(INADDR ANY);serv_addr.sin_port=htons(atoi(argv[1]));if(bind(serv_sock,(struct sockaddr*)&serv_addr, sizeof(serv_addr))==-1)error_handling("bind() error");if(listen(serv sock,5)==-1)error_handling("listen() error");clnt addr size=sizeof(clnt addr);cInt sock=accept(sery sock,(struct sockaddr*)&cInt addr,&cInt addr size);if(clnt sock==-1)error_handling("accept() error");write(clnt_sock,message,sizeof(message));close(clnt sock);close(serv sock);return 0;
}
void error handling(char *message)
{fputs(message, stderr);fputc('\n',stderr);exit(1);
}
2.客户端
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
void error handling(char *message);
int main(int argc, char* argv[])
{int sock;struct sockaddr_in serv_addr;char message[30];int str_len;if(argc!-3){printf("Usage :%s<IP><port>\n",argv[0]);exit(1);}sock=socket(PF INET,SOCK STREAM, 0);if(sock == -1)error_handling("socket() error")memset(&serv addr,0,sizeof(serv addr));serv addr.sin family=AF INET;serv addr.sin addr.s addr-inet addr(argv[1]);serv_addr.sin port=htons(atoi(argv[2]));if(connect(sock,(struct sockaddr*)&serv addr,sizeof(serv_addr))==-1)error_handling("connect() error!");str len=read(sock,message,sizeof(message)-1);if(str len=--1)error_handling("read()error!");printf("Message from server :Xs n",message);close(sock);return 0;
}
void error handling(char*message)
{fputs(message, stderr)fputc('\n',stderr);exit(1);
}
三、Qt实现TCP通信
相对于前边两种方法，QT进行了一定封装，使用起来更加简洁。
1.服务端
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtNetwork>
#if _MSC_VER >= 1600
#pragma execution_character_set("utf-8")
#endifQString MainWindow::getLocalIP()
{//获取本机IPv4地址//! 本地主机名, QHostInfo 的静态函数 localHostName()可获取本机的主机名QString hostName = QHostInfo::localHostName();//! 返回指定的主机名的IP地址QHostInfo hostInfo = QHostInfo::fromName(hostName);QString localIP = "";//! 返回与 hostName()主机关联的IP地址列表QList<QHostAddress> addList = hostInfo.addresses();//for (int i = 0; i < addList.count(); i++){QHostAddress aHost = addList.at(i);if (QAbstractSocket::IPv4Protocol == aHost.protocol()){//192.168.23.114localIP=aHost.toString();break;}}return localIP;
}void MainWindow::closeEvent(QCloseEvent *event)
{//关闭窗口时停止监听if (tcpServer->isListening())tcpServer->close();;//停止网络监听event->accept();
}MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);LabListen=new QLabel("监听状态:");LabListen->setMinimumWidth(150);ui->statusBar->addWidget(LabListen);LabSocketState=new QLabel("Socket状态：");//LabSocketState->setMinimumWidth(200);ui->statusBar->addWidget(LabSocketState);//本机IPQString localIP = getLocalIP();this->setWindowTitle(this->windowTitle()+"----本机IP："+localIP);ui->comboIP->addItem(localIP);//! tcp服务端tcpServer = new QTcpServer(this);//! 如果有新的连接connect(tcpServer, SIGNAL(newConnection()), this, SLOT(onNewConnection()));
}MainWindow::~MainWindow()
{delete ui;
}//! 服务端有新的连接时
void MainWindow::onNewConnection()
{
// ui->plainTextEdit->appendPlainText("有新连接");//! 创建socket,返回下一个等待接入的连接tcpSocket = tcpServer->nextPendingConnection();//! connectToHost()成功连接到服务器后发射此信号,连接成功后显示connect(tcpSocket, SIGNAL(connected()), this, SLOT(onClientConnected()));//! 客户端接入时onClientConnected();//! 当socket断开连接后发射此信号connect(tcpSocket, SIGNAL(disconnected()), this, SLOT(onClientDisconnected()));//! 当socket的状态变化时发射此信号,参数socketState表示了socket当前的状态connect(tcpSocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)), this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));onSocketStateChange(tcpSocket->state());//! 当缓冲区有新数据需要读取时发射此信号，在此信号的槽函数里读取缓冲区的数据connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(onSocketReadyRead()));
}//socket状态变化时
void MainWindow::onSocketStateChange(QAbstractSocket::SocketState socketState)
{switch(socketState){case QAbstractSocket::UnconnectedState:LabSocketState->setText("scoket状态：UnconnectedState");break;case QAbstractSocket::HostLookupState:LabSocketState->setText("scoket状态：HostLookupState");break;case QAbstractSocket::ConnectingState:LabSocketState->setText("scoket状态：ConnectingState");break;case QAbstractSocket::ConnectedState:LabSocketState->setText("scoket状态：ConnectedState");break;case QAbstractSocket::BoundState:LabSocketState->setText("scoket状态：BoundState");break;case QAbstractSocket::ClosingState:LabSocketState->setText("scoket状态：ClosingState");break;case QAbstractSocket::ListeningState:LabSocketState->setText("scoket状态：ListeningState");}
}//客户端接入时
void MainWindow::onClientConnected()
{ui->plainTextEdit->appendPlainText("**client socket connected");ui->plainTextEdit->appendPlainText("**peer name:" + tcpSocket->peerName());//! 在已连接状态下，返回对方socket的地址ui->plainTextEdit->appendPlainText("**peer address:" + tcpSocket->peerAddress().toString());ui->plainTextEdit->appendPlainText("**peer port:" + QString::number(tcpSocket->peerPort()));
}void MainWindow::onClientDisconnected()
{//客户端断开连接时ui->plainTextEdit->appendPlainText("**client socket disconnected");tcpSocket->deleteLater();// deleteLater();//QObject::deleteLater();
}void MainWindow::onSocketReadyRead()
{//读取缓冲区行文本
// QStringList lines;while(tcpSocket->canReadLine())ui->plainTextEdit->appendPlainText("[in] " + tcpSocket->readLine());
// lines.append(clientConnection->readLine());
}//开始监听
void MainWindow::on_actStart_triggered()
{//! IP地址QString IP = ui->comboIP->currentText();//! 端口quint16 port = ui->spinPort->value();QHostAddress addr(IP);tcpServer->listen(addr, port);//
// tcpServer->listen(QHostAddress::LocalHost,port);// Equivalent to QHostAddress("127.0.0.1").ui->plainTextEdit->appendPlainText("**开始监听...");ui->plainTextEdit->appendPlainText("**服务器地址：" + tcpServer->serverAddress().toString());ui->plainTextEdit->appendPlainText("**服务器端口：" + QString::number(tcpServer->serverPort()));ui->actStart->setEnabled(false);ui->actStop->setEnabled(true);LabListen->setText("监听状态：正在监听");
}void MainWindow::on_actStop_triggered()
{//停止监听if (tcpServer->isListening()) //tcpServer正在监听{tcpServer->close();//停止监听ui->actStart->setEnabled(true);ui->actStop->setEnabled(false);LabListen->setText("监听状态：已停止监听");}
}void MainWindow::on_actClear_triggered()
{ui->plainTextEdit->clear();
}void MainWindow::on_btnSend_clicked()
{//发送一行字符串，以换行符结束QString msg=ui->editMsg->text();ui->plainTextEdit->appendPlainText("[out] "+msg);ui->editMsg->clear();ui->editMsg->setFocus();QByteArray str=msg.toUtf8();str.append('\n');//添加一个换行符tcpSocket->write(str);
}void MainWindow::on_actHostInfo_triggered()
{//获取本机地址QString hostName=QHostInfo::localHostName();//本地主机名ui->plainTextEdit->appendPlainText("本机主机名："+hostName+"\n");QHostInfo hostInfo=QHostInfo::fromName(hostName);QList<QHostAddress> addList=hostInfo.addresses();//if (!addList.isEmpty())for (int i=0;i<addList.count();i++){QHostAddress aHost=addList.at(i);if (QAbstractSocket::IPv4Protocol==aHost.protocol()){QString IP=aHost.toString();ui->plainTextEdit->appendPlainText("本机IP地址："+aHost.toString());if (ui->comboIP->findText(IP)<0)ui->comboIP->addItem(IP);}}}mainwindow.h```cpp
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QTcpServer>
#include <QLabel>namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{Q_OBJECT
private:QLabel *LabListen;//状态栏标签QLabel *LabSocketState;//状态栏标签QTcpServer *tcpServer; //TCP服务器QTcpSocket *tcpSocket;//TCP通讯的SocketQString getLocalIP();//获取本机IP地址
protected:void closeEvent(QCloseEvent *event);
public:explicit MainWindow(QWidget *parent = 0);~MainWindow();
private slots:
//自定义槽函数void onNewConnection();//QTcpServer的newConnection()信号void onSocketStateChange(QAbstractSocket::SocketState socketState);void onClientConnected(); //Client Socket connectedvoid onClientDisconnected();//Client Socket disconnectedvoid onSocketReadyRead();//读取socket传入的数据
//UI生成的void on_actStart_triggered();void on_actStop_triggered();void on_actClear_triggered();void on_btnSend_clicked();void on_actHostInfo_triggered();
private:Ui::MainWindow *ui;
};#endif // MAINWINDOW_H1.客户端
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QHostAddress>
#include <QHostInfo>
#if _MSC_VER >= 1600
#pragma execution_character_set("utf-8")
#endif
QString MainWindow::getLocalIP()
{QString hostName = QHostInfo::localHostName();//本地主机名QHostInfo hostInfo = QHostInfo::fromName(hostName);QString localIP = "";QList<QHostAddress> addList = hostInfo.addresses();//for (int i = 0; i < addList.count(); i++){QHostAddress aHost = addList.at(i);if (QAbstractSocket::IPv4Protocol == aHost.protocol()){localIP=aHost.toString();break;}}return localIP;
}
void MainWindow::closeEvent(QCloseEvent *event)
{if (tcpClient->state()==QAbstractSocket::ConnectedState)tcpClient->disconnectFromHost();event->accept();
}MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);tcpClient = new QTcpSocket(this); //创建socket变量LabSocketState=new QLabel("Socket状态：");//状态栏标签LabSocketState->setMinimumWidth(250);ui->statusBar->addWidget(LabSocketState);//本机IPQString localIP = getLocalIP();this->setWindowTitle(this->windowTitle() + "----本机IP：" + localIP);ui->comboServer->addItem(localIP);connect(tcpClient,SIGNAL(connected()),this,SLOT(onConnected()));connect(tcpClient,SIGNAL(disconnected()),this,SLOT(onDisconnected()));connect(tcpClient,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));connect(tcpClient,SIGNAL(readyRead()),this,SLOT(onSocketReadyRead()));
}MainWindow::~MainWindow()
{delete ui;
}void MainWindow::onConnected()
{ //connected()信号槽函数ui->plainTextEdit->appendPlainText("**已连接到服务器");ui->plainTextEdit->appendPlainText("**peer address:" + tcpClient->peerAddress().toString());ui->plainTextEdit->appendPlainText("**peer port:" + QString::number(tcpClient->peerPort()));ui->actConnect->setEnabled(false);ui->actDisconnect->setEnabled(true);
}void MainWindow::onDisconnected()
{//disConnected()信号槽函数ui->plainTextEdit->appendPlainText("**已断开与服务器的连接");ui->actConnect->setEnabled(true);ui->actDisconnect->setEnabled(false);
}void MainWindow::onSocketReadyRead()
{//readyRead()信号槽函数while(tcpClient->canReadLine())ui->plainTextEdit->appendPlainText("[in] "+tcpClient->readLine());
}void MainWindow::onSocketStateChange(QAbstractSocket::SocketState socketState)
{//stateChange()信号槽函数switch(socketState){case QAbstractSocket::UnconnectedState:LabSocketState->setText("scoket状态：UnconnectedState");break;case QAbstractSocket::HostLookupState:LabSocketState->setText("scoket状态：HostLookupState");break;case QAbstractSocket::ConnectingState:LabSocketState->setText("scoket状态：ConnectingState");break;case QAbstractSocket::ConnectedState:LabSocketState->setText("scoket状态：ConnectedState");break;case QAbstractSocket::BoundState:LabSocketState->setText("scoket状态：BoundState");break;case QAbstractSocket::ClosingState:LabSocketState->setText("scoket状态：ClosingState");break;case QAbstractSocket::ListeningState:LabSocketState->setText("scoket状态：ListeningState");}
}void MainWindow::on_actConnect_triggered()
{//连接到服务器QString addr=ui->comboServer->currentText();quint16 port=ui->spinPort->value();tcpClient->connectToHost(addr,port);
// tcpClient->connectToHost(QHostAddress::LocalHost,port);
}void MainWindow::on_actDisconnect_triggered()
{//断开与服务器的连接if (tcpClient->state()==QAbstractSocket::ConnectedState)tcpClient->disconnectFromHost();
}void MainWindow::on_actClear_triggered()
{ui->plainTextEdit->clear();
}void MainWindow::on_btnSend_clicked()
{//发送数据QString msg=ui->editMsg->text();ui->plainTextEdit->appendPlainText("[out] "+msg);ui->editMsg->clear();ui->editMsg->setFocus();QByteArray str = msg.toUtf8();str.append('\n');tcpClient->write(str);
}mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QTcpSocket>
#include <QLabel>namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{Q_OBJECT
private:QTcpSocket *tcpClient; //socketQLabel *LabSocketState; //状态栏显示标签QString getLocalIP();//获取本机IP地址
protected:void closeEvent(QCloseEvent *event);
public:explicit MainWindow(QWidget *parent = 0);~MainWindow();private slots:
//自定义槽函数void onConnected();void onDisconnected();void onSocketStateChange(QAbstractSocket::SocketState socketState);void onSocketReadyRead();//读取socket传入的数据
//void on_actConnect_triggered();void on_actDisconnect_triggered();void on_actClear_triggered();void on_btnSend_clicked();private:Ui::MainWindow *ui;
};#endif // MAINWINDOW_H总结
以上就是今天要讲的内容，本文整理了三种实现TCP通信的方法，从上层到偏底层，对于新手理解通信原理有极大帮助。
